expansion joints

[poynton phil]

I'v got 2 rooms joined by a door, ones 6.1mx5m, the other is 8mx5m, will i be ok with 1 expasion joint in the joining door threshold, there will be a 10mm gap around the perimiter. the tiles are 800x800 porcelain going on to a heated anhydrite screed

 

[Qwerty]

My understanding is that for a heated s&c screed the floor area should be divided up by movement joints into bays of no greater than 40 m² in size with an edge length not exceeding 8 metres. BS States that all movement joints should be continuous throughout the screed bed, adhesive and tile covering.

But for heated anhydrite screeds, joints should be placed at intervals of no greater than 20 linear meters with an aspect ratio of no more than 6:1. Additional joints should be placed at door thresholds and between independently controlled heating zones. Additional joints should be considered at points where heated meets unheated screed and in areas of other than usual thermal gain e.g. Conservatories or glass roofed rooms.

(Above anhydrite info was pinched from an old post by AJAX btw![emoji106]) I'm sure AJAX will confirm or clarify with any up to date current guidelines though.

So from that info above I interpret that a joint at the doorway as you planned will be fine.

 

[Ajax123]

I concur

 

[Qwerty]

[emoji106]